a few small clippy fixes

compiler/rustc_ast_lowering/src/index.rs

@@ -125,9 +125,9 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
 }
 
 impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
-    /// Because we want to track parent items and so forth, enable
-    /// deep walking so that we walk nested items in the context of
-    /// their outer items.
+    // Because we want to track parent items and so forth, enable
+    // deep walking so that we walk nested items in the context of
+    // their outer items.
 
     fn visit_nested_item(&mut self, item: ItemId) {
         debug!("visit_nested_item: {:?}", item);

compiler/rustc_errors/src/emitter.rs

@@ -2322,11 +2322,6 @@ impl HumanEmitter {
                 show_code_change
             {
                 for part in parts {
-                    let snippet = if let Ok(snippet) = sm.span_to_snippet(part.span) {
-                        snippet
-                    } else {
-                        String::new()
-                    };
                     let span_start_pos = sm.lookup_char_pos(part.span.lo()).col_display;
                     let span_end_pos = sm.lookup_char_pos(part.span.hi()).col_display;
 
@@ -2402,7 +2397,7 @@ impl HumanEmitter {
                         // LL - REMOVED <- row_num - 2 - (newlines - first_i - 1)
                         // LL + NEWER
                         //    |         <- row_num
-
+                        let snippet = sm.span_to_snippet(part.span).unwrap_or_default();
                         let newlines = snippet.lines().count();
                         if newlines > 0 && row_num > newlines {
                             // Account for removals where the part being removed spans multiple

compiler/rustc_hir_analysis/src/variance/terms.rs

@@ -44,7 +44,7 @@ impl<'a> fmt::Debug for VarianceTerm<'a> {
     }
 }
 
-/// The first pass over the crate simply builds up the set of inferreds.
+// The first pass over the crate simply builds up the set of inferreds.
 
 pub(crate) struct TermsContext<'a, 'tcx> {
     pub tcx: TyCtxt<'tcx>,

compiler/rustc_lint/src/passes.rs

@@ -55,10 +55,10 @@ macro_rules! late_lint_methods {
 /// Each `check` method checks a single syntax node, and should not
 /// invoke methods recursively (unlike `Visitor`). By default they
 /// do nothing.
-//
+///
 // FIXME: eliminate the duplication with `Visitor`. But this also
 // contains a few lint-specific methods with no equivalent in `Visitor`.
-
+//
 macro_rules! declare_late_lint_pass {
     ([], [$($(#[$attr:meta])* fn $name:ident($($param:ident: $arg:ty),*);)*]) => (
         pub trait LateLintPass<'tcx>: LintPass {

compiler/rustc_middle/src/mir/consts.rs

@@ -16,7 +16,7 @@ use crate::ty::{self, ConstKind, GenericArgsRef, ScalarInt, Ty, TyCtxt};
 
 ///////////////////////////////////////////////////////////////////////////
 /// Evaluated Constants
-
+///
 /// Represents the result of const evaluation via the `eval_to_allocation` query.
 /// Not to be confused with `ConstAllocation`, which directly refers to the underlying data!
 /// Here we indirect via an `AllocId`.

compiler/rustc_target/src/spec/targets/armv6k_nintendo_3ds.rs

@@ -5,7 +5,6 @@ use crate::spec::{
 /// A base target for Nintendo 3DS devices using the devkitARM toolchain.
 ///
 /// Requires the devkitARM toolchain for 3DS targets on the host system.
-
 pub(crate) fn target() -> Target {
     let pre_link_args = TargetOptions::link_args(
         LinkerFlavor::Gnu(Cc::Yes, Lld::No),

compiler/rustc_target/src/spec/targets/armv7_sony_vita_newlibeabihf.rs

@@ -7,7 +7,6 @@ use crate::spec::{
 /// A base target for PlayStation Vita devices using the VITASDK toolchain (using newlib).
 ///
 /// Requires the VITASDK toolchain on the host system.
-
 pub(crate) fn target() -> Target {
     let pre_link_args = TargetOptions::link_args(
         LinkerFlavor::Gnu(Cc::Yes, Lld::No),